The Irish Times reported Sunday that the suit, filed earlier this month in New South Wales, concerns alleged nonpayment of stud fees, and Kildangan issued a statement stating only that the case “is a commercial matter . . . relating to Thoroughbred stallion nominations.”

It’s the latest blow to Tinkler’s Patinack Thoroughbred racing and breeding operation, which has suffered along with Tinkler’s other financial holdings as the price of coal – and the value of his coal-based assets – has dropped.

Tinkler, a former mining electrician, made his fortune in the mining business and is the largest shareholder in Whitehaven Coal, in which he has a 19.4 percent interest. That stake, valued at more than $1 billion Australian last year, is now thought to be worth half that after a steep decline in coal prices.

Tinkler and his Australian representatives have said he intends to stay in the horse business, although the Australian press has reported that courts have appointed liquidators both for Patinack and Tinkler’s Mulsanne Resources company.

Kildangan Stud, located in County Kildare, Ireland, is part of Sheikh Mohammed’s international Darley breeding operation.